1. Field of the Invention
The present invention relates to an idle stop & go (ISG) system, and more particularly, to an ISG system capable of enhancing driving convenience and fuel efficiency through the improvement of ISG logic.
2. Description of Related Art
An ISG system in the related art is an engine control system which automatically turns off an engine when an idle state of the engine is maintained during a predetermined time or more after a vehicle is stopped, and then automatically turns on the engine when a restart of the engine is requested by a driver's intention or a vehicle's condition.
That is, the ISG system turns off the engine in a preset stoppage delay time when the vehicle is stopped after driving in a state where an ISG operation condition is satisfied. Such an ISG-related condition is applied in the same manner, regardless of driving patterns.
However, even when a driver intends to temporarily stop the vehicle during driving without an idle stop, for example, when the vehicle is moved back and forth in a parking lot or is stopped by a stop signal in North America, the ISG system turns off the engine in case where the stoppage time satisfies the stoppage delay time condition of the ISG logic. Accordingly, the driving convenience is degraded.
Further, as shown in FIG. 1, the ISG system in the related art has problems in that, when the vehicle is restarted immediately after engine stop, hesitation is caused by starter drive, and fuel consumption for restart is increased by an unnecessary idle stop.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.